[PATCH 4/5] drm/tyr: set DMA mask using GPU physical address

[Deborah Brouwer]

From: Beata Michalska <beata.michalska@xxxxxxx>

Configure the device DMA mask during probe using the GPU's physical
address capability reported in GpuInfo. This ensures DMA allocations
use an appropriate address mask.

Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Reviewed-by: Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx>
Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
Signed-off-by: Beata Michalska <beata.michalska@xxxxxxx>
Co-developed-by: Deborah Brouwer <deborah.brouwer@xxxxxxxxxxxxx>
Signed-off-by: Deborah Brouwer <deborah.brouwer@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/tyr/driver.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/tyr/driver.rs b/drivers/gpu/drm/tyr/driver.rs
index cdb9b13bdb32..e20a5978eed6 100644
--- a/drivers/gpu/drm/tyr/driver.rs
+++ b/drivers/gpu/drm/tyr/driver.rs
@@ -11,6 +11,10 @@
         Device, //
     },
     devres::Devres,
+    dma::{
+        Device as DmaDevice,
+        DmaMask, //
+    },
     drm,
     drm::ioctl,
     io::{
@@ -124,6 +128,14 @@ fn probe(
         let gpu_info = GpuInfo::new(pdev.as_ref(), &iomem)?;
         gpu_info.log(pdev.as_ref());
 
+        let pa_bits = MMU_FEATURES::from_raw(gpu_info.mmu_features)
+            .pa_bits()
+            .get();
+        // SAFETY: No concurrent DMA allocations or mappings can be made because
+        // the device is still being probed and therefore isn't being used by
+        // other threads of execution.
+        unsafe { pdev.dma_set_mask_and_coherent(DmaMask::try_new(pa_bits)?)? };
+
         let platform: ARef<platform::Device> = pdev.into();
 
         let data = try_pin_init!(TyrDrmDeviceData {

-- 
2.53.0